Hummock; heap (5)
I believe the answer is:
mound
I believe this is a double definition.
'hummock' is the first definition.
(I know that hummock can be written as mound)
'heap' is the second definition.
(I know that heap can be written as mound)
(Other definitions for mound that I've seen before include "Mass of piled-up earth or stones" , "Hillock; gold ball (Her.)" , "Small hill, large pile" , "Heap, hillock" , "Heap (of raised earth)" .)